On Thu, Feb 14, 2013 at 08:28:03PM +0100, Igor Mammedov wrote: > On Thu, 14 Feb 2013 13:13:18 +0100 > Paolo Bonzini <pbonz...@redhat.com> wrote: > > > Il 14/02/2013 12:18, Eduardo Habkost ha scritto: > > >> > qemu boots from disk image 3 times faster than direct kernel load. > > > That's surprising. Do you have any idea why that happens? > > > > Because kernel load uses MMIO (from fw_cfg), while booting from disk > > uses at worst PCI DMA and at best virtio. > > > > Paolo > I've tried Paolo's suggestion to run in TCG mode with instruction logging, > and it spends too much time reading 11K kernel from qemu compared to > kvm-unit-test kernel. I'll need debug it further to find out why. > But this patch looks unnecessary if I could fix qemu/seabios or test kernel > to reach the same load time as kvm-unit-test kernel.
Agreed. Lucas, please don't apply this patch yet, until we find the actual cause of the slow booting. -- Eduardo
